Backpack



FIG. 1 is a perspective view of a backpack showing the new design;

FIG. 2 is a front view of the backpack shown in FIG. 1 ;

FIG. 3 is a right side view of the backpack shown in FIG. 1 ;

FIG. 4 is a back view of the backpack shown in FIG. 1 ;

FIG. 5 is a left side view of the backpack shown in FIG. 1 ;

FIG. 6 is a top view of the backpack shown in FIG. 1 ; and,

FIG. 7 is a bottom view of the backpack shown in FIG. 1 . 

CLAIM The ornamental design for a backpack, as shown and described. 